Perhaps you should try some spelling variations:
thang tai » hang tai, tang tai, thanh tai
van thang » van thanh, van khang, van hang
dong xay » cong xay, mong xay, dong xa
dang xay » dang van, van xay
so sach » so sanh, bo sach, co sach
cao duc » dao duc, cao suc, tao duoc
hieu va » lieu va, hieu qua
sach ha » sach nha, sach han, sach xa
cuc te » cua te, cuc thue, cuc tieu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ha ((dong xay) or (dang xay)) hoi. hieu va ((cao duc) OR (giao duc)) van thang tai cuc te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ha ((dong xay) OR (dang xay)) hoi. hieu va ((cao duc) OR (giao duc)) van thang tai cuc te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ha ((dong xay) or (dang xay)) hoi. hieu va ((cao duc) OR (giao duc)) van thang tai cuc te".
• Adding a wildcard symbol may retrieve word variants: so sach ha ((dong xay) or (dang xay)) hoi. hieu va ((cao duc) OR (giao duc)) van thang tai cuc te*.